Conventional internal combustion engines employ a carburetor for mixing air with the fuel and a manifold for distributing the mixture to the engine. The carburetor includes a venturi with fuel inlet openings provided downstream from the venturi. The venturi creates a partial vacuum to draw raw fuel through the fuel inlet openings into the airstream where it is mixed with the airstream as it passes through the manifold to the engine. Since the fuel enters the airstream as a mist or small fuel droplet, complete mixture does not occur thus resulting in incomplete combustion of the fuel in the engine. Maximum air fuel ratios in a conventional carburetor are in the order of 16 to 1. It has also been established that a completely vaporized fuel will produce greater efficiencies of combustion and air fuel ratios can be increased to 22 to 1. At the higher air fuel ratios, greater combustion occurs with the vaporized fuel because of the better distribution of the fuel throughout the internal combustion engine cylinders which also results in a lowering of the concentration of hydrocarbon and a carbon monoxide emissions from the engine.
Attempts at lowering emissions from internal combustion engines have been directed to the use of catalytic converters in the exhaust system and exhaust gas recycling systems for completing combustion of the fuel prior to exhausting the gas to the atmosphere. However, these systems do not add to the useful work available from the engine, but increase the load on the engine resulting in a reduced efficiency in miles per gallon achievable by the engine.
Fuel vaporizing carburetor of a type similar to the present invention are disclosed in U.S. Pat. No. 3,653,643, issued Apr. 4, 1972 entitled "Carburetor" and U.S. Pat. No. 3,892,547 issued July 1, 1975 entitled "Vaporizing Carburetor." Both of these carburetors have proven effective in increasing fuel efficiency for short periods of time. Difficulties have been experienced in fuel control and in regulating the fuel-air ratio.